Interlocking relay



Oct. 11, 1938. I. w CLAUS 2,132,528

7 I INTERLOGKING RELAY Filed March 5, 1956 2 Sheets-Sheet 1 INVENTOR m'llz'am H. Claw.

H16 ATTORNEY Patented Oct. 11, 1938 PATENT OFFICE IN TERLOCKING RELAY William H. Claus, Down to The Union Switch &

vale, Pa., a corporation ers Grove, Ill., assignor Signal Company, Swissof Pennsylvania Application March 3, 1936, Serial No. 66,835

12 Claims.

My invention relates to interlocking relays, and particularly to interlocking relays in which three armatures controlled by three separate electromagnets are interconnected by mechanical means 5 in such manner that when a predetermined one of said armatures moves away from its associated electromagnet, it restricts the subsequent movement of either of the two remaining armatures away from its associated electromagnet.

I will describe one form of relay embodying my invention, and one circuit arrangement employing the relay and also embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a view partly diagrammatic and partly in isometric projection showing one form of relay embodying my invention. Fig. 2 is a diagrammatic view showing one circuit arrangement in which the relay illustrated in Fig. 1 may be employed.

Similar reference characters refer to similar parts in both views.

Referring first to Fig. 1, the relay, which is designated as a whole by the reference character R, comprises, in the form here shown, three electromagnets A, B, and C mounted end for end on a top plate I of suitable insulating material, such for example, as a phenol condensation product. The electromagnets A, B, and C are similar, and. the corresponding parts of each are designated by the same reference characters with the distinguishing exponents a, b, and 0 added thereto.

It is believed, therefore, that a description of one electromagnet will sufiice for all. Referring par- 35 ticularly to the electromagnet A, this electromagnet comprises two parallel cores 2 connected together at their upper ends by a backstrap 3 and provided at their lower ends with enlarged pole pieces 4 located on the underside of the top plate I. The cores 2" each carry a winding or coil 5*, which windings are intended to be connected in series in the usual and well-known manner.

A non-magnetizable bracket 6 is attached to the rear sides of the pole pieces 4*, and pivotally supported on trunnion screws l mounted in depending lugs 8 provided on the ends of the bracket 6 is a tractive armature 9 which carries a plurality of contact fingers m Il l2**, and I3 When the electromagnet' A is energized, the armature 9 is drawn upwardly to the position in which it is shown in the drawings, and under these conditions the contact fingers IO Il I2 and l3 each engage an associated fixed contact member M to close front contacts |0 I4 ll l4 l2 l4 and Ili -J4. When, however,

the electromagnet A is deenergized, the armature 9 drops downwardly under the influence of gravity, and except under certain conditions which will be described hereinafter, the contact fingers Ill H H and l3 then each engage an associ ated fixed contact member I5 to close back contacts Ill -I5 ll l5 l2 l5 and l3 l5 The contact fingers l0, Il l2, and l3 are socured to the armature 9 by means of insulating supports I6, and it will be apparent, therefore, that these contact fingers are insulated from the armature and from each other.

The electromagnets B and C control armatures 9 and 9, respectively, which armatures are pivotally supported in a manner similar to the armature 9, and each of which carries contact fingers which cooperate with fixed front and back contact members to close front and back contacts in the same manner that the contact fingers I0 H I2 and l3 carried by the armature 9 cooperate with fixed front contact members M and back contact members l5 to close front and back contacts.

The armatures 9 and 9 are interlocked by interlocking mechanism comprising two arms 30 and 3 l which are attached, respectively, to these armatures, and which cooperate with a locking dog I'l pivotally mounted on a shaft I8 The dog I1 is provided with a horizontal arm I9 and a vertical arm and is biased to rotate, in a counter-clockwise direction, to an inoperative position in which the vertical arm 20 engages a stop arm 38 by a counterweight 2 l which is secured to the outer end of the horizontal arm I9 The inner end of the arm I9 is provided with an upstanding projection 22 which cooperates with a resilient strip 23 attached to the interlocking arm 3l When the armature 9 is released and drops, the flexible strip 23 engages the projection 22 of the horizontal arm I9 of the dog I1 shortly after the armature passes its mid-stroke position, and during the remainder of the downward stroke of the armature, the dog I1 is rotated in a clockwise direction, in opposition to the bias exerted by the counterweight 2l to an operative position in which the upper end of the vertical arm 20 is in the path of downward movement of an offset portion 24 forming a part of the arm If armature 9 is then released, the downward movement of this armature will be limited by engagement of the offset portion 24 with the upper end of the vertical arm 20 The parts are so proportioned that when the offset portion 24 enges the vertical arm 20 in this manner, the armature 9* will be held at approximately its mid-stroke position, and both the front and back contacts controlled by the armature 9 will then be open. Furthermore, when the oifset portion 24 engages the vertical arm 23 in this manner, a tip 25 formed on the end of a retaining spring 26 attached to the arm 3& extends downwardly past the outer edge of the upper end of the vertical arm 2B thusholding the dog in place underneath the offset portion 2 3 and thereby insuring that armature 9 cannot move to the position in which its back contacts are which position the vertical arm 29 is out of the path of movement of the offset portion 2& If armature 9 is released and drops before armature 9 the offset portion 24 will move downwardly past the upper end of the arm 23 of the dog 11 but the tip 25 of the retaining spring 28 will engage the upper end of the arm 29 The retaining spring 26 howevenis very flexible, and it will be apparent, therefore, that it will oifer very little resistance to the downward movement of the armature 9 so that the armature will close its back contacts under these conditions with substantially the same contact pressure as would be the case if the interlocking arm 3E were not attached to the armature.

The armatures 9 and 9 are interlocked by interlocking mechanism which is similar in all respects to, and which operates in, the same manner as, that just described for interlocking the armatures 9 and 9 The various parts of the mechanism for interlocking the armatures 9 and 9 are designated by the same reference characters as the corresponding parts of the mechanisms for interlocking the armatures 9 and 9 but with the exponent 2 added, and it is believed, therefore,- that a detailed description of the mechanism for interlocking the armatures 9 and 9 is unnecessary. 7

It. should be pointed out that the dogs I'l and I! are very light in weight and are loosely' pivoted on the associated shafts I8 and I8 so that the force required to drive these dogs is small. The flexible strips 23 and 23 need only be stiif enough to drive the dogs H and H without causing deflection of the strips, and it will be apparent, therefore, that these strips may be constructed to bend under sufficiently small pressures so that they will not prevent the armature 9 from closing its back contacts even though one of the dogs H or [T2 is prevented from rotating to its full operative position due to the armature 9 or the armatureS having previously been released. If desired, backstops 28 and 28 of rigid material may be provided to determine accurately the position at which the strips 23 and 23 will engagethe associateddogs I1 and H during the downward stroke of the armature 9 Furthermore, topstops 29 and 29 may also be provided with clearance above the strips, so that if some unusual resistance to the movement of the dogs should develop that would cause abnormal deflection of the strips 23 and I 23 the associated topstop 29 or 29 would engage the strips and would limit the amount of.

deflectiongof the strips so that the corresponding 7 locking dog would still be driven into the path of movement, of the associated offset portion 24 or-24 and past the tips25 and 25 of the retaining springs 26 and 26 It will be seen from the foregoing that with the relay constructed in the manner described, if either electromagnet A or electromagnet C becomes deenergized before electromagnet B, the armature 9 or the armature 9 as. the case may be, will drop to its lowermost position in which "past the position in which the associated front and back contacts are all open.

Relays embodying my invention are particularly suitable for, although in no way limited to, use for controlling highway crossing signals, and in Fig. 2 I have shown one way in which a relay embodying my invention may be used to control such a signal. Referring to Fig. 2, the reference characters 32 and 33 designate the track rails of a stretch S of railway track over which traffic normally moves in both directions. The rails 32 and 33 are divided by means of insulated joints 34 to form three adjacent track sections D-E,

E'F, and F-G, the middle section E--F being relatively short and being intersected by a highway H.

Section DE is provided with a track circuit comprising a battery 35, connected across the rails adjacent the end of the section which is farthest away from the highway H, and the magnet C of an interlocking relay R similar to the relay R shown in Fig. 1, connected across the rails, at the end nearest the highway H, in series with front contact Ni -M of relay R Section FG is provided with a similar circuit which includes a battery 36, the rails of the section, magnet A of relay R and front contact I t -M of relay R Section E-F. is provided with a track circuit which includes a battery 31 connected across the rails at one end of the section, and the magnet B .of relay R connected across the rails at the other end of the section. I U A signal L which, as here shown, is an electric bell, is located adjacent the intersection of the highway H and the stretch'S, and this signal is provided with a circuit which includes a battery J and back contacts m -i5 l3 -l5 and l3 l5 of relay R connected in parallel. It will be apparent, therefore, that when all of the back.

shunt will cause magnet A to become deener-.

gized, and back contact l3=*|5 of relay R will therefore become closed and will cause bell L to' start to ring. When the train enters section E-F, magnet B will become deenergized and will cause the front contacts of relay R controlled by this magnet to open and the back contacts controlled by this magnet to become closed. The opening of front contact Il li will interrupt the circuit for magnet A, and will thus cause magnet A to remain deenergized as long as magnet B remains deenergized. The opening of front contact Hi l i will interrupt the circuit for magnet C, and will thus cause magnet C to also become deenergized. The deenergization of this latter magnet will cause the frontcontacts of relay R controlledvthereby to open, but the back contacts controlled thereby will remain open due to the interlocking mechanism. The closing of back contact I 3 l will close the circuit for bell L at this contact, but since the circuit for bell L is already closed at back contact lit -l5, the closing of back contact l3"l5 will have no effeet on the remainder of the apparatus. As the train continues to traverse the stretch S, no further change in the apparatus will take place until the rear end of the train clears section E-F. When this happens, magnet B will become energized and will cause the back contacts controlled thereby to open and the front contacts controlled thereby to close. The closing of front contact I l'--|4 will restore the circuit forthe magnet A, while the closing of front contact Ill l4 will restore the circuit for magnet C. Magnet A will then pick up and open its back contacts and close its front contacts, but magnet C will remain deenergized due to the train shunt. When back contact N -I5 opens, back contacts li -I5 and |3 |5 will both be open, and as a result, the circuit for bell L will become interrupted, so that the bell will stop ringing. When the train departs from section DE, magnet C will become energized and will cause the front contacts controlled thereby to become closed. All parts of the apparatus will then be restored to the positions in which they are shown in the drawings.

When a train traverses the stretch S from left to right, the operation of the apparatus is similar to that just described, and it is believed that this operation will be apparent from the foregoing description and from an inspection of the drawings without further detailed scription.

It will be seen from the foregoing that a train approaching the crossing H in either direction will cause the bell L to start ringing as soon as the train enters either section DE or F-G, and the bell will continue to ring until the train has completely passed section EF.

It will be noted that as shown in Fig. 2 the magnets A and C are slow releasing magnets.

1e reason for making these magnets slow releasing is to insure that the armatures controlled by these magnets will not drop quickly enough to cause the interlocking apparatus to fail to function when either of these magnets becomes deenergized due to the previous deenergization of magnet B. The relay will, however, usually function in the proper manner when the magnets A and C are of the ordinary acting type.

It should also be noted that since the deenergization of magnet B causes the circuits for both magnets A and C to become interrupted, back contact Hi -45 or back contact lil -l5 will always be closed when contact Ni -45 is closed, and as a result, the bell L will function in the manner described whether or not contact I3 l 5 is included in the circuit for bell L, the only reason for including this contact in the circuit for bell L being to provide an additional degree of protection against improper operation of the apparatus.

One advantage of controlling a highway crossing signal by means of a relay embodying my invention in the manner shown in Fig. 2 is that the directional selection for cutting off the operation of the highway crossing signal is made at the crossing proper, thus eliminating circuit lockouts due to train movements in sections DE and F-G. This is particularly desirable where a switch is located in either section DE or section F-G, since the reversal of the switch while a train is in the other section, or the entry of a train into the other section while the switch is reversed, will not prevent a warning from being given at the crossing as long as the train has not proceeded past the crossing to the position in which it clears section E-F.

Although I have herein shown and described only one form of interlocking relay embodying my invention and one circuit arrangement employing relays embodying my invention, it is understood that various changes and modifications may be made both in the relay and in the circuit arrangement within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. An interlocking relay comprising three electromagnets, three armatures one movable toward and away from each electromagnet according as such electromagnet is energized or deenergized, means for connecting one of said armatures with each of the two remaining armatures in such manner that releasing movement of said one armature away from its associated electromagnet will cause the subsequent releasing movement of either one of the two remaining armatures away from its associated electromagnet to be restricted, and two back contacts one operated by each of said two remaining armatures and each arranged to close when the associated armature is fully released and to remain open when the releasing movement of that armature is restricted as aforesaid.

2. An interlocking relay comprising three electromagnets, three armatures one controlled by each electromagnet, two resilient members attached to one of said armatures, two dogs one actuated by each resilient member, two back contacts one operated by each of the two remaining armatures and each arranged to close when and only when the associated armature is fully released, and rigid means separately controlled by said two remaining armatures and separately coacting with said dogs for restricting the releasing movement of both of those remaining armatures when the said dogs are actuated by the said resilient members attached to said one armature whereby to prevent closure of the said back contacts which said remaining armatures operate.

3. An interlocking relay comprising three electromagnets, three armatures one controlled by each electromagnet, two resilient members attached to one of said armatures, two dogs one actuated by each resilient member when said one armature moves away from its associated electromagnet, two back contacts one operated by each of the two remaining armatures and each arranged to close when and only when the associated armature is'fully released, and means separately controlled by said two remaining armatures and separately coacting with said dogs in such manner that movement of either one of said two remaining armatures away from its associated electromagnet will be restricted when the associated dog is actuated by the associated member and the said back contacts which said remaining armatures operate will thereby be prevented from closing.

4. An interlocking relay comprising three electromagnets, three armatures one controlled by each of said electromagnets, two dogs each capable of assuming a plurality of positions, resilient means attached to a first one of said armatures for moving said dogs from a first position to a second position when said first armature releases, two back contacts one operated by each of the two remaining armatures and each arranged to close when and only when the associated armature is fully released, and separate rigid means separately attached to said two remaining armatures and separately cooperating with said two dogs for restricting the releasing movement of the armature to which the rigid means is attached when the cooperating dog occupies its second position whereby to prevent closure of both of said back contacts which said remaining armatures operate.

5. An interlocking relay comprising three electromagnets, three armatures one movable toward and away from each electromagnet according as such electromagnet is energized or deenergized, two movable dogs, two resilient members attached to a first one of said armatures and separately coacting with said dogs for at times moving said dogs from a first position to a secend position when said first armature moves away from its associated electromagnet, two back contacts one operated by each of the two remaining armatures and each arranged to close when and only when the associated armature is fully released, and rigid means separately controlled by said two remaining armatures and separately 'coacting with said dogs for restricting the releasing movement of either one of said two remaining armatures away from its associated electromagnet when and only when said first armature has previously moved away from its associated electromagnet whereby to prevent closure under that condition of the said back contacts which said remaining armatures operate.

6. An interlocking relay comprising three electromagnets, three armatures one movable toward and away from each electromagnet according as such electromagnet is energized or deenergized, two movable dogs, two resilient members attached to a first one of said armatures and separately coacting with said dogs for at times moving said dogs from a first position to a second position when said first armature moves away from its associated electromagnet, two back contacts one operated by each of the two remaining armatures and each arranged to close when and only when the associated armature is fully released, and two rigid members; one attached to each of said two remaining armatures and each cooperating with a difierent one of said dogs in such manner that the releasing movement of either of said two remaining armatures away from its-associated electromagnet will be restricted when the associated dog occupies its second position but not when the associated dog occupies its first position whereby the said back contacts which said two remaining armatures operate will be prevented from closing if said first armature has previously moved away from its associated electromagnet.

7. An interlocking relay comprising three electromagnets, three armatures one movable toward and away from each electromagnet according as such electromagnet is energized or deenergized, a first and a second dog reach biased to a first position, a first resilient strip attached to a first one of said armatures and cooperating with said first dog for at times moving said first dog from its first position to a second position when said first armature moves away from its associated electromagnet, a second resilient strip attached to said first armature and cooperating with said second dog for at other times moving-said second dog from its first position to a second position when said first armature moves away from its associated electromagnet, two back contacts one operated by each of the second and third of said armatures and each arranged to-close when and only when the armature which operates it is fully released, a first rigid member secured to said second armature and cooperating with said first dog to restrict the movement of said second armature away from its associated electromagnet when said'first dog occupies its second position whereby to prevent closure under that condition of the said back contact which the second armature operates, a second rigid member secured to said third armature and cooperating with said second dog to restrict the movement of said third armature away from its associated electromagnet when said second dog occupies its second position whereby to prevent closure under that condition of the said back contact which the third armature operates, said first and second resilient strips being constructedto yield if the resistance to movement of the dog controlled thereby exceeds its normal value. 1 a

8. An interlocking relay comprising first, second, and third electromagnets; first, second, and third armatures movable toward and away from said first, second, and third electromagnets, respectively, according as the associated electromagnet is energized or deenergized; a first and a second locking dog each having a first and a second position, a first resilient strip attached to said first armature and effective when said first armature moves away from said first electromagnet for exerting a force on said first dog which tends to move it from its first to its second position, a second'resilient strip attached to said first armature and effective when said first armature moves away from said first electromagnet for exerting a force on'said second dog which tends to move it from its first to its second position, two back contacts one operated by each of said second and third armatures and each arranged to close when and only when the armature which operates it is fully released, means attached to said second armature and cooperating with said first dog when said first dog occupies its second position for limiting the movement of said second armature away from said second electromagnet whereby to prevent closure under that condition of the said back contact which the second armature operates, and means attached to said third armature and cooperating with said second dog when said second dog occupies its second position for limiting the movement of said third armature away from said third electromagnet whereby to prevent closure under that condition of the said back contact which the third armature operates.

9. An interlocking relay comprising first, second, and third armatures controlled by first, second, and third electromagnets, respectively; a first pivoted locking dog having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also having a vertical arm, a first resilient strip attached to said first armature and coacting with said first dog. at said projection for actuating said first dog, a back contact operated by said second armature and arranged to close when and only when that armature is fully released, a first interlocking arm attached to said second armature and provided with an ofiset portion for at times engaging the vertical arm of said first dog when said first dog is actuated whereby to limit the releasing movement of said second armature and thereby prevent closure of the said back contact which is associated therewith, a second pivoted looking dog having a horizontal arm provided at one end with a counterweight and at the other end with an upstanding projection and also having a vertical arm, a second resilient strip attached to said first armature and coacting with said second dog at said projection for actuating said second dog, a back contact operated by said third armature and arranged to close when and only when that armature is fully released, and a second interlocking arm attached to said third armature and provided with an offset portion for at times engaging the vertical arm of said second dog when said second dog is actuated whereby to limit the movement of said third armature and thereby prevent closure of the said back contact which is associated therewith.

10. An interlocking relay comprising a first, a second and a third electromagnet, each or" said magnets having associated therewith an armature which is moved toward the magnet to a picked up position when the magnet is energized and which is biased away from the magnet to a released position when the magnet is deenergized, each of the armatures of said first and third electromagnets having associated therewith a back contact which closes when and only when the armature is fully released, each of said first and third armatures also having associated therewith a latching member which is movable between an inactive position and a latching position and which is operable in its latching position to restrict releasing movement of the armature and thereby prevent closure of the said back contact which is associated with that armature, biasing means for normally maintaining each of said latching members in its inactive position, and means operable on movement of the armature of said second electromagnet to its released position for moving both of said latching members from their inactive to their latching positions.

11. An interlocking relay comprising a first, a second and a third electromagnet, each of said magnets having associated therewith an armature which is moved toward the magnet to a picked up position when the magnet is energized and which is biased away from the magnet to a released position when the magnet is deenergized, each of the armatures of said first and third electromagnets having associated therewith a back contact which closes when and only when the armature is fully released, a latching member associated with the armature of said first electromagnet and being movable from an inactive position to a latching position in which it restricts releasing movement of said first armature and thereby prevents closure of the said back contact which is associated with that armature, a latching member associated with the armature of said third electromagnet and also being movable from an inactive position to a latching position in which it restricts releasing movement of said third armature and thereby prevents closure of the said back contact which is associated with that armature, biasing means for normally maintaining each of said latching members in its inactive position, and means operable on movement of the armature of said second eiectromagnet to its released position for moving both of said latching members from their inactive to their latching positions.

12. An interlocking relay comprising a central electromagnet, two end electromagnets respectively positioned on opposite sides of said central magnet, each of said three magnets having associated therewith an armature which is moved toward the magnet to a picked up position when the magnet is energized and which is biased away from the magnet to a released position when the magnet is deenergized, each of the armatures of said two end magnets having associated therewith a back contact which closes when and only when the armature is fully released, each of said end armatures also being provided with a latching member which is movable between an inactive position and a latching position and which is operable in its latching position to restrict releasing movement of the associated armature and thereby prevent closure of the said back contact which is associated with that armature, means for normally biasing each of said latching members to its inactive position, and means operable on movement of the armature of said central electromagnet toits released position for moving both of said latching members from their inactive to their latching positions.

WILLIAM H. CLAUS. 

